|Scatter Radar: Space Research From The Ground - United States. National Bureau of Standards|
Scatter Radar: Space Research From The Ground"Tells the story of Jicamarca Observatory, new National Bureau of Standards facility near Lima, Peru, and its fascinating new research projects. Jicamarca, largest institution of its kind in the world, uses a 22 acre antenna, probes the upper atmosphere to measure electron densities, makes observations of planets, and studies solar coronas and solar gases...
Keywords: HAARP; Scatter Radar; Ionosphere; DXing; Over The Horizon Radar; Cold War
|A Conceptual Design For A Spaceborne 3D Imaging Lidar - Degnan, John J|
First generation spaceborne altimetric approaches are not well-suited to generating the few meter level horizontal resolution and decimeter accuracy vertical (range) resolution on the global scale desired by many in the Earth and planetary science communities. The present paper discusses the major technological impediments to achieving few meter transverse resolutions globally using conventional approaches and offers a feasible conceptual design which utilizes modest power kHz rate lasers, array...
Keywords: ELECTROSTATIC PROBES; IONOSPHERIC TEMPERATURE; ELECTRON DENSITY PROFILES; ALGORITHMS; DATA REDUCTION; INTERNATIONAL SPACE STATION; INCOHERENT SCATTER RADAR; IONOSONDES
|A Low-noise Micromachined Millimeter-Wave Heterodyne Mixer using Nb Superconducting Tunnel Junctions - DeLange, Gert|
A heterodyne mixer with a micromachined horn antenna and a superconductor-insulator-superconductor (SIS) tunnel junction as mixing element is tested in the W-band (75-115 GHz) frequency range. Micromachined integrated horn antennas consist of a dipole antenna suspended on a thin Si3N4 dielectric membrane inside a pyramidal cavity etched in silicon. The mixer performance is optimized by using a backing plane behind the dipole antenna to tune out the capacitance of the tunnel junction...
Keywords: SATELLITE OBSERVATION; BOUNDARY CONDITIONS; DENSITY DISTRIBUTION; INCOHERENT SCATTER RADAR; MOLECULAR IONS; EXPLORER 2 SATELLITE; IONIZATION; ELECTRON DENSITY (CONCENTRATION); SPACECRAFT MODELS; PHOTOCHEMICAL REACTIONS; NEUTRAL ATMOSPHERES; THERMOSPHERE; ATMOSPHERIC DENSITY
|Probing the antiferromagnetic long-range order with Glauber spin states - Cabrera, Guillermo G|
It is well known that the ground state of low-dimensional antiferromagnets deviates from Neel states due to strong quantum fluctuations. Even in the presence of long-range order, those fluctuations produce a substantial reduction of the magnetic moment from its saturation value. Numerical simulations in anisotropic antiferromagnetic chains suggest that quantum fluctuations over Neel order appear in the form of localized reversal of pairs of neighboring spins...
Keywords: AURORAL IONIZATION; DMSP SATELLITES; F REGION; PLASMA DENSITY; RADAR DATA; TEMPERATURE DISTRIBUTION; TEMPERATURE MEASUREMENT; ELECTRIC FIELDS; ELECTRON PRECIPITATION; INCOHERENT SCATTER RADAR; MAGNETOSPHERE-IONOSPHERE COUPLING; RADAR SCATTERING; RADAR TRACKING; SATELLITE OBSERVATION; SOLAR WIND
|NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 41: Technical communication practices of Dutch and US aerospace engineers and scientists: International perspective on aerospace - Barclay, Rebecca O.|
As part of Phase 4 of the NASA/DOD Aerospace Knowledge Diffusion Research Project, studies were conducted that investigated the technical communications practices of Dutch and U.S. aerospace engineers and scientists. The studies had the following objectives: (1) to solicit the opinions of aerospace engineers and scientists regarding the importance of technical communication to their professions, (2) to determine the use and production of technical communication by aerospace engineers and scienti...
Keywords: AURORAL ARCS; DMSP SATELLITES; ELECTRIC FIELDS; ELECTRODYNAMICS; INCOHERENT SCATTER RADAR; MAGNETIC FIELDS; PLASMA LAYERS; RADAR MEASUREMENT; ROCKET SOUNDING; SATELLITE-BORNE PHOTOGRAPHY; CONVECTION; ELECTRON PRECIPITATION; FIELD ALIGNED CURRENTS; MAGNETOSPHERE-IONOSPHERE COUPLING; PLASMA DYNAMICS; POLAR REGIONS; SPECTRAL SIGNATURES; AURORAS